Improvement in the treatment of plow mold-boards



J. S. ROBINSON.

TREATMENT OF PLOW MQLD-BO ARDS No.17 7,961. Patented May 30,1876.

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JOHN s. ROBINSON, 0F CANANDAIGUA, NEW YORK.

IMPROVEMENT IN THE TREATMENT QFIPLOW MOLD-BOARDS.

Specification forming part of Letters Patent No. 177,961, dated May 30, 1876; application filed March 27, 1876.

To all whom it may concern:-

Be it known that I, J OHN' S. Bonnvson, of Canandaigua, in the county of Ontario and I State of New York, have invented a certain new and-useful Process for the Treatment of Mold-Boards of Flows and other castings;

and do hereby declare that the following is .a

full, clear, and exact description thereof, which will enable others skilled in the art to which it pertains tomake and use the same, reference being had to the accompanying drawings, and

to the letters of reference marked thereon,

which form a part of this specification, in

' .which- This invention relates to a process for thetreatment of the'mold-boards of plows and other castings, previous to their being removedfrom' the flask or mold in which they are formed; and it consists in chilling'a portion thereof,

- and the application to such chilled surfaces of a highly-heated piece of metal or other equivalent substance, while that portion of the. cast,

'ing which 'is uponthe opposite side to that which was in contact with the chill'when cast is in a plastic or semi-fluid condition, or while the casting is yet at a red heat, the object be ing to prevent the unequal cooling thereof and the consequent unequal shrinking and strain upon the same, as well as the change of form likely to result from such unequal cooling.

In making mold-boards of plows and treating them according to my process I use a bottom board, A, which maybe of any desired form, and of any suitable substance, such as wood or metal, andof sufficientdimensions to receive upon its upper surface aflask, B,

in which to place the sand. Upon this bottom board-the chill 0 is placed, the uppersurface v of which is to be of aform adapted to receive the outer surface of the mold-board, while its lower surface is of such form as to allow it to rest upon the board, or upon the sand when no bottom board is used.

The chill 0 having been placed in position in the mold, the pattern D is placed thereon,

as shown in Fig. 1, when sand is packed around its edges and sloped down to the bottom board, and the flask B is then filled with sand, which mulation of any moisturethereon, and to expel any that may accumulate in the space Within the mold, when the chill is returned to the mold, the flask replaced, and the metal poured in while the chill is yet warm,by which operation the. metal of the lower side of the casting is brought in contact with the chill B, and is quickly set and at the same time hardened, while the metal on its opposite side will for some time remain in .a plastic or semi-fluid state; and in order to avail myself of this fact, I at once turn the flask over, or to such an angle as to make it convenient to remove the chill, and to apply a highly-heated plate of metal, or other equivalent substance, to that portion of the casting from which the chill has been removed, the effect being to prevent the further rapid cooling of that surface, and thus allow all parts of the casting to cool evenly, the resultof which is that when the casting is removed from its moldit retains its full strength, it not being weakened by unequalstrain in cooling, or subjected to a change of form by such strain.

The plate E, which it is proposed to apply in the heated condition referred to, is shown in Fig. 4, it being supplied with handles, as shown, for convenience in handling. This plate E may be made of metal, of such materia-l as fire-bricks are composed of, or of any material that has-,sufficient adhesion in its particles to admit of its being handled, and that will retain a suflicient amount of heat to produce the required effect upon the casting, and hence If'do not limit my invention to the material out of which said plate is made. In order that this plate may produce the best possible effect it isimportant that it should be applied as soon aspossibl'e'aftcr the surface with which it is to be placed in contact has become solidified, and while the metal upon the opposite side is still in the state describedQin order-that the lengths of the surfaces may not-be changed by the un-;

' equal cooling of the two sides.

I have. described the bottom board and the chill as consisting of separate parts, but it is apparent that they may be made of one piece of metal; or the chill may be used without any bottom board, it being placed upon the sand or floor of the foundry; but as those devices form no part of my present invention,

they need not be more particularly described here. r Having thus d cseribedmy invention, Whtts I claim is [II-he herein-described process for treating,

mold-board's of plows and'other castings, it

consisting in the application to the chilledsurface or surfaces of such castings, of a conforming-plate of highly-heated material, while w'th'e unchillied' portion is-still-in a plastic state,

or while the Whole is at a red heat, and before it has been removed from the flask or inold in which it was formed, substantially in the-manner and for the purpose specified.

In testimony that Iclaim the foregoing as myown invention I aiilx my signature:inpresw-ence of two witnesses.

JOHN S. ROBINSON. Witnesses:

I 0. CONN-ELL, ELIHU WILDER-L 

